[SOLVED] not to suspend when lid close

As far as I know, this should something concerning with acpi. I searched on the web, but most of the articles either mention how to configure acpid or report bugs.

I ran acpid -d -l, the messages seem to me that it ran correctly ( correct conf, receiving signal, calling script).My script (/etc/acpi/handler.sh) is just the default script which I think it do nothing, and I added a test cmd "echo LID >> /etc/acpi/debug" to ensure the script is called and works.

It seems to me that something other than acpid also handle the lid close signal.Could anyone give me some ideas? Thanks in advanced.